30 Years Solid State Physics

Peter's Anniversary in November 2017


(so schön war die vorlesungsfreie Zeit .. )

Exactly 30 years ago the first publication from results of our research on high temperature superconductors was published in Solid State Communication (see below). This was also my first published paper from ultrasound experiments that started during my Diploma thesis in the group of Prof. Ewert and Prof. Sander at the Phys. Inst. of the RWTH Aachen. The work has been performed in collaboration with the Phillips Research Laboratory in Aachen (Group of Dr. A. Comberg and Dr. J. Pankert) and the group of Prof. Arlt (Electrical Engineering, RWTH Aachen). These were the good old times .. 

Unfortunately my favored chequered trousers are lost in time.


SOLID STATE COMMUNICATIONS 64 (8): 1153-1156 NOV 1987,

88 citations in Web of Science. (in 2007)


Ultrasonic velocity and attenuation measurements down to 4.2 K were performed on well characterized ceramic superconducting YBa2Cu3O7-δ samples of different microstructure. In fine grained samples of high volume density and excellent superconducting properties no softening in the sound velocity and no thermal hysteresis were found. A broad maximum at about 180 K and an anomaly near Tc were observed in the ultrasonic attenuation.



Impressum - Back to the Webpages of Peter Lemmens -  15.10.2007